/* 
 *  Copyright 2012 CodeMagi, Inc.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package com.codemagi.servlets.validation;

import com.codemagi.servlets.AppException;
import com.codemagi.util.Utils;
import java.util.List;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;

/**
 * Validate that an input parameter is not null
 */
public class NotNullValidator implements IValidator {

    private String errorMessage = "Please enter all required information."; 

    public NotNullValidator() {}

    public NotNullValidator(String errorMessage) {
	this.errorMessage = errorMessage;
    }

    public Object validate(Object obj, HttpServletRequest request) throws AppException {

	if (obj == null) throw new AppException(errorMessage);

	if (obj instanceof String && Utils.isEmpty((String)obj) ) throw new AppException(errorMessage);

	if (obj instanceof List && Utils.isEmpty((List)obj) ) throw new AppException(errorMessage);

	if (obj instanceof Set && Utils.isEmpty((Set)obj) ) throw new AppException(errorMessage);

	return obj;
    }

}
